Should You Repair or Replace Your Roof?

When repair is usually the right answer

Most roofs we are called to do not need replacing. A roof with a specific defect and an otherwise serviceable covering is a repair job, and treating it as one is both cheaper and entirely proper.

Repair may be appropriate when

• The problem is localised to one area rather than spread across the roof
• Individual slates or tiles have slipped or cracked but the rest are well fixed
• A specific detail has failed — a valley, a flashing, a chimney abutment or an upstand
• Damage followed a storm rather than gradual deterioration
• The underlay and battens are in reasonable condition where they can be seen
• The roof has not needed repeated attention in the same place

When replacement needs to be considered

Replacement comes into the picture when the covering as a whole is at the end of its serviceable condition, rather than when one part of it has failed.

Replacement may need considering when

• Deterioration is widespread rather than confined to one slope or area
• Slates or tiles are slipping in different places each winter — often nail fatigue across the roof
• The underlay has perished, so the roof has no secondary line of defence
• Repairs have become a recurring annual expense
• Several details are failing at once and the covering around them is brittle
• The covering is visibly breaking down — delamination, crumbling, widespread cracking
• Major related work is already planned, such as an attic conversion

A simple way to think about it

None of the points below are absolute, and roofs frequently sit between the two columns. They are a way of framing the conversation rather than a verdict.

The cost of repeated patching

A single repair is almost always better value than a replacement. Several repairs a year, each with its own access cost, stop being better value fairly quickly — and the water getting in between visits does its own damage to timbers, plaster and insulation.

That is the practical calculation: not repair versus replacement in principle, but this repair against the likely pattern of the next few winters. An honest roofer will give you their view on that pattern.

Why an inspection usually settles the question

Most of the evidence that decides this is not visible from the ground or from the ceiling stain. The condition of the fixings, the underlay, the battens and the details is what tells you whether a roof has years left in it.

We will tell you when a roof can be repaired, including when we have been called out because someone else said it needed replacing. See roof inspections.

What each route involves

Repair work is usually short, contained and sometimes possible without full scaffolding. Replacement means stripping the covering, renewing battens and underlay, re-detailing valleys, verges and chimneys, and scaffolding to the relevant elevations.

For costs, see the roof repair cost guide and the new roof cost guide. For the work itself, see roof repairs, new roofs and slate roof replacement.

Repair or replace: a quick comparison

A general guide only. Roofs often show signs from both columns, which is why an inspection matters.